This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Pilgrimage site for star-crossed lovers.

Hidden in the back of a disused small town hotel is a dive bar shellacked with over a million pennies.

This massive underground salt mine now holds a sci-fi theme park in its depths.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The curious underground history of keeping Paris clean.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

The black lab that was voted mayor of a California town is forever remembered by a life-size statue.

A Roman-inspired temple once controlled half of San Francisco's waters.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.